title: Chemical composition and antioxidant properties of Laurus nobilis L. and Myrtus communis L. essential oils from Morocco and evaluation of their antimicrobial activity acting alone or in combined processes for food preservation.
abstract: BACKGROUND
  This study describes the antioxidant and antimicrobial activity of Laurus nobilis L. and Myrtus communis L. essential oils (EOs). This is the first report of the synergistic antimicrobial effect of these EOs in combination with physical food preservation treatments.
  
  
  RESULTS
  EOs obtained by steam distillation from aerial parts of Laurus nobilis and Myrtus communis were analysed by using gas chromatography-mass spectrometry. The main compounds were 1,8-cineole and 2-carene (L. nobilis EO); and myrtenyl acetate, 1,8-cineole and α-pinene (M. communis EO). L. nobilis EO showed higher antioxidant activity than M. communis EO in three complementary antioxidant tests. Although antimicrobial activity tests demonstrated the effectiveness of L. nobilis EO and the lack of bactericidal effect of M. communis EO, synergistic lethal effects were observed when combining each EO (0.2 µL mL(-1)) with mild heat (54°C for 10 min) or high hydrostatic pressure (175-400 MPa for 20 min). In contrast, combination of EOs with pulsed electric fields (30 kV cm(-1) for 25 pulses) showed no additional effects.
  
  
  CONCLUSIONS
  This study shows the great potential of these EOs in combined treatments with mild heat and high hydrostatic pressure to obtain a higher inactivation of foodborne pathogens, which might help in the design of safe processes applied at low intensity.
authors.affiliation: Université Abdelmalek Essaâdi, Faculté des Sciences et Techniques, Equipe de Recherche en Biotechnologies et Génie des Biomolécules (ERBGB), B.P. 416, Tanger, Morocco.
authors.forename: Lamia
authors.initials: L
authors.lastname: Cherrat
authors.forename: Laura
authors.initials: L
authors.lastname: Espina
authors.forename: Mohammed
authors.initials: M
authors.lastname: Bakkali
authors.forename: Diego
authors.initials: D
authors.lastname: García-Gonzalo
authors.forename: Rafael
authors.initials: R
authors.lastname: Pagán
authors.forename: Amin
authors.initials: A
authors.lastname: Laglaoui
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D000081008:Bicyclic Monoterpenes; D003511:Cyclohexanols / Q000032:analysis / Q000494:pharmacology; D000077591:Eucalyptol; D005519:Food Preservation / Q000379:methods*; D005517:Foodborne Diseases / Q000382:microbiology; D006358:Hot Temperature; D006801:Humans; D027442:Laurus / Q000737:chemistry*; D039821:Monoterpenes / Q000032:analysis / Q000494:pharmacology*; D009018:Morocco; D031651:Myrtus / Q000737:chemistry*; D009822:Oils, Volatile / Q000737:chemistry / Q000494:pharmacology*; D035261:Plant Components, Aerial; D011312:Pressure
chemical_list: D000900:Anti-Bacterial Agents; D000975:Antioxidants; D000081008:Bicyclic Monoterpenes; D003511:Cyclohexanols; D039821:Monoterpenes; D009822:Oils, Volatile; C113988:2-carene; C005451:alpha-pinene; D000077591:Eucalyptol
keywords: antimicrobial activity; antioxidant activity; chemical composition; combined treatments; emerging technologies; essential oils; heat preservation